Composite substrate carrier

ABSTRACT

A composite wafer carrier according to an embodiment of the present invention comprises an operative portion formed of a first thermoplastic material and a support portion formed of a second different thermoplastic material. One of the operative portion and support portion is overmolded onto the other to form a gapless hermitic interface that securely bonds the portions together. The operative portion may be a transparent window, a portion of a latching mechanism or a wafer contact portion. Preferred embodiments of the invention include wafer carriers with said features, process carriers with said features and a process for manufacturing wafer carriers with said features.

REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of U.S. patentapplication Ser. No. 09/317,989, filed on May, 25, 1999, issuing as U.S.Pat. No. 6,428,729 on Aug. 6, 2002, which is based on U.S. ProvisionalApplication Serial No. 60/087,205, filed May 28, 1998. Each of thesereferences is hereby incorporated in their entirety herein.

FIELD OF THE INVENTION

[0002] This invention relates to devices for confining memory disk,silicon wafers, and the like for transport, storage, processing. Moreparticularly the invention relates to a composite wafer or disk carrier.

BACKGROUND OF THE INVENTION

[0003] Certain carriers are utilized for transporting and storingbatches of silicon wafers or magnetic disks before, during, and afterprocessing of the disks or wafers. The wafers are processed intointegrated circuits and the disks are processed into a magnetic storagedisks for computers. Wafers when used herein refers to silicon wafers,magnetic substrates, and the like.

[0004] The processing of wafer disks into integrated circuit chips ofteninvolves several steps where the disks are repeatedly processed, storedand transported. Due to the delicate nature of the disks and theirextreme value, it is vital that they are properly protected throughoutthis procedure. One purpose of a wafer carrier is to provide thisprotection. Additionally, since the processing of wafer disks isgenerally automated, it is necessary for disks to be preciselypositioned relative to the processing equipment for the robotic removaland insertion of the wafers. A second purpose of a wafer carrier is tosecurely hold the wafer disks during transport.

[0005] Carriers are generally configured to axially arrange the wafersor disks in slots, and to support the wafers or disks by or near theirperipheral edges. The wafers or disks are conventionally removable fromthe carriers in a radial direction upwardly or laterally. Carriers mayhave supplemental to covers, bottom covers, or enclosures to enclose thewafers or disks. There are a number of material characteristics, whichare useful and advantageous for wafer carriers depending on the type ofcarrier and the particular part of the carrier at issue.

[0006] During processing of semiconductor wafers or magnetic disks, thepresence of or generation of particulates presents very significantcontamination problems. Contamination is accepted as the single biggestcause of yield loss in the semiconductor industry. As the size ofintegrated circuitry has continue to be reduced, the size of particleswhich can contaminate an integrated circuit has also become smallermaking minimization of contaminants all the more critical. Contaminantsin the form of particles may be generated by abrasion such as therubbing or scraping of the carrier with the wafers or disks, with thecarrier covers or enclosures, with storage racks, with other carriers,or with the processing equipment. A most desirable characteristic of acarrier is therefore a resistance to particle generation upon abrasion,rubbing, or scraping of the plastic molded material. U.S. Pat. No.5,780,127 discusses various characteristics of plastics which arepertinent to the suitability of such materials for wafer carriers. Saidpatent is incorporated by reference.

[0007] Carrier materials should also have minimal outgassing of volatilecomponents as these may leave films which also constitute a contaminantwhich can damage wafers and disks. The carrier materials must haveadequate dimensional stability, that is rigidity, when the carrier isloaded.

[0008] Dimensional stability is necessary to prevent damage to thewafers or disks and to minimize movement of the wafers or disks withinthe carrier. The tolerances of the slots holding wafers and disks aretypically quite small and any deformation of the carrier can directlydamage the highly brittle wafers or can increase the abrasion and thusthe particle generation when the wafers or disks are moved into, out of,or within the carrier. Dimensional stability is also extremely importantwhen the carrier is loaded in some direction such as when the carriersare stacked during shipment or when the carriers integrate withprocessing equipment. The carrier material should also maintain itsdimensional stability under elevated temperatures, which may beencountered during storage or cleaning.

[0009] Conventional carriers used in the semiconductor industry maydevelop and retain static charges. When a charged plastic part comesinto contact with an electronic device or processing equipment it maydischarge in a damaging phenomena known as electrostatic discharge(ESD). Additionally, statically charged carriers may attract and retainparticles, particularly airborne particles. Also static buildup oncarriers can cause semiconductor processing equipment to automaticallyshut down. It is most desirable to have a carrier with staticdissipation characteristics to eliminate ESD and to avoid attractingparticles.

[0010] Trace metals are a common ingredient or residue in many potentialwafer carrier materials. Metal contamination must be considered inmaterial selection and assembly methods of carriers. Anion contaminationin carrier materials can cause contamination and corrosion problems.

[0011] Material used in carriers must also be chemically compatible toany chemicals which they may be subjected to. Although transport andstorage wafer carriers are not intended for chemical use they must beresistant to cleaning solutions and commonly used solvents such asisopropyl alcohol. Process carriers are subject to ultra pure acids andother harsh chemicals.

[0012] Visibility of wafers within closed containers is highly desirableand may be required by end users. Transparent plastics suitable for suchcontainers, such as polycarbonates, are desirable in that such plasticis low in cost but such plastics do not have desirable staticdissipative characteristics nor desirable abrasion resistance. Otherimportant characteristics include the cost of the carrier material andthe ease of molding the material.

[0013] Carriers are typically formed of injection molded plastics suchas polycarbonate (PC), acrylonitrile butadiene styrene (ABS),polypropylene (PP), polyethylene (PE), perfluoroalkoxy (PFA), andpolyetheretherketone (PEEK). Fillers which have been added to injectionmolded plastics for static dissipation include carbon powder or fiber,metal fibers, metal coated graphite, and organic (amine-based)additives.

[0014] One common conventional wafer carrier used for transport andstorage is a single molded part generally comprising a front end havingan H-bar interface portion, a back end having a panel, and sidewallshaving slots and lower curved or converging portions following thecurvature of the wafers, and with an open top and open bottom. H-barcarriers will often be reused several times and then discarded. Betweenuses the carriers will typically be washed in hot wafer and/or otherchemicals and they are then dried with hot air. It is a valuablecharacteristic to have a carrier that holds it shape when subjected tothe higher temperatures associated with the cleaning, drying,transporting, and processing the carriers. Another conventional carrieris a box configured to hold an H-bar carrier. Such boxes are commonlyknown as work-in-process (WIP) boxes.

[0015] Another conventional carrier is a standardized mechanicalinterface (SMIF) pod which is comprised of a box which sealinglyencloses an H-bar carrier which mechanically interfaces with processequipment. SMIF pods typically have a bottom opening door for accessingthe H-bar carrier with wafers. Boxes are also known which have frontopening doors for accessing the H-bar carrier.

[0016] Yet another conventional carrier is a front opening unified pod(FOUP), such as that disclosed in U.S. Pat. No. 6,010,008, to Nyseth etal, which is hereby incorporated by reference. FOUPs generally comprisea front opening container having a plurality of wafer supportingstructures provided to the interior thereof. The wafer supportingstructures maintain the wafers in an approximately horizontalorientation. A separate H-bar structure is not needed for FOUPs due tothe presence of the internal support structures.

[0017] It must be recognized that the ideal material for one part of acarrier is typically not the ideal material for a different part of thesame carrier. For example, PEEK is a material that has ideal abrasionresistance characteristics ideal for wafer contact portions but isdifficult to mold and is, relative to other plastics, very expensive.Thus, PEEK may not be as good of a choice as other plastics, such apolycarbonate, for structural portions.

[0018] The only instances that different materials are known to havebeen used for different portions of disk carriers is by separatelymolding the different portions then assembling them into a carrier. Suchassembly presents the disadvantage of surface to surface contact ofdifferent components which can create particle or contaminant entrapmentareas that are difficult to clean. Moreover, molding of plastic partsoften creates components that are not perfectly uniform. Thus assemblyof components can leave gaps and typically such assembly requiresmechanical fasteners of some sort. Additionally, the assembly processcan generate particles. Moreover, the molding of different componentparts and assembling same in a carrier involves labor and thus expense.

[0019] SUMMARY OF THE INVENTION

[0020] A composite wafer carrier according to an embodiment of thepresent invention comprises an operative portion formed of a firstthermoplastic material and a support portion formed of a seconddifferent thermoplastic material. One of the operative portion andsupport portion is overmolded onto the other to form a gapless hermiticinterface that securely bonds the portions together. The operativeportion may be a transparent window, a portion of a latching mechanismor a wafer contact portion. Preferred embodiments of the inventioninclude wafer carriers with said features, process carriers with saidfeatures and a process for manufacturing wafer carriers with saidfeatures.

[0021] A composite wafer carrier according to an embodiment of thepresent invention comprises a base portion formed of a firstthermoplastic material. The base portion defines a plurality of slotsfor holding wafers in an axially aligned position. The base includes atransparent window thermophysically bonded to the base. The windowallows a user to view wafers within the carrier. The base may alsoinclude a cover to seal the wafers within the wafer carrier. The coverincludes a latching assembly. The latching assembly includes a bearinghub comprised of an abrasion resistant material that is provided to thedoor by way of an overmolding or co-injection molding operation.

[0022] An advantage and feature of particular embodiments of the presentinvention is that a carrier may be formed that provides optimalperformance characteristics at minimal material and labor costs.

[0023] An additional feature and advantage of particular embodiments ofthe present invention is that there is no assembly of component partswhile maintaining the advantages of using the combination of the twomaterials.

[0024] An additional feature and object of particular embodiments of thepresent invention is that a substantially integral carrier or componentis created by the two plastic portions which are molded together.

[0025] Another advantage and feature of particular embodiments of thepresent invention is that the juncture between the two dissimilarmaterials is closed eliminating the potential entrapment of contaminantsor other chemicals.

[0026] An additional object and advantage of particular embodiments ofthe present invention is that a viewing window may be provided to aportion of a wafer container.

[0027] Another object and feature of particular embodiments of thepresent invention is that the process can eliminate post moldingconditioning of wafer carriers that otherwise could be necessary, suchas annealing.

[0028] Another object and feature of particular embodiments of thepresent invention is that the overmolded components are gapless,hermetic and very secure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is an H-bar wafer carrier according to an embodiment of thepresent invention.

[0030]FIG. 2 is a figure showing the overmolded portion of the carrierof FIG. 1.

[0031]FIG. 3 is a perspective view of a prior art work-in-process (WIP)box according to an embodiment of the present invention.

[0032]FIG. 4 is a perspective view of a WIP box and an H-bar accordingto an embodiment of the present invention.

[0033]FIG. 5 is a side elevational view of a WIP box in according to anembodiment of the present invention.

[0034]FIG. 6 is a perspective view of a prior art disk shipper accordingto an embodiment of the present invention.

[0035]FIG. 7 is the body of a disk shipper in accordance with theinvention.

[0036]FIG. 8 is a prior art view of transport module.

[0037]FIG. 9 is an exploded view of a transport module similar to whatis shown in FIG. 8 according to an embodiment of the present invention.

[0038]FIG. 10 is a perspective view of a composite wafer carrieraccording to an embodiment of the present invention.

[0039]FIG. 11 is an exploded view of the wafer carrier of FIG. 10.

[0040]FIG. 12 is a perspective view of a process enhancement carrieraccording to an embodiment of the present invention.

[0041]FIG. 13 is a schematic illustrating the methodology of anembodiment of the present invention.

[0042]FIG. 14 is a perspective view of a front opening unified pod(FOUP) style wafer carrier having an insert molded transparent windowaccording to an embodiment of the prior art.

[0043]FIG. 15 is an assembly view of a door for a wafer carrieraccording to an embodiment of the present invention.

[0044]FIG. 16 is an perspective view of a cover for a wafer enclosurewith a latching mechanism according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE DRAWINGS

[0045] Referring to FIG. 1 an H-bar wafer carrier is depicted and isgenerally indicated with the numeral 20. This carrier has, as inconventional H-bar carriers, a front 22, a back 23, side walls 24, 26,slots for receiving wafers 28, an open top 30, and a machine interfaceportion configured as an H-bar 32. Each of the slots is defined by apair of wafer engaging teeth 34.

[0046] The traditional H-bar wafer carrier has in addition to the H-barmachine interface, a bottom machine interface 38 which will typicallyhave four feet with a contact at the corners 40. Additionally, a roboticpick-up handle 42 and robotic flanges 44 also function as machineinterfaces. The composite H-bar carrier generally has a support portionof first base portion 44 and a second overmolded portion 46 configuredas wafer engaging portions 46. In this embodiment the wafer carrier 20is a single integral component 20.

[0047] Referring to FIG. 2 the overmolded portion 50 is shown withoutthe integral base portion and comprises an operative portion configuredas wafer engaging portions 46 as well as incidental portions 52 whichconstitute flow paths for the molten overmold material during the moldprocess. This portion, as shown, reflects the configuration of the moldcavity for the overmolding.

[0048] In a preferred embodiment, the support or base portion 44 will bemolded of an inexpensive dimensionally stable easily molded plastic suchas polycarbonate or polycarbonate with carbon fiber filler. Then theovermolded portion can be molded from another melt processablecrystalline plastic such as PEEK or PEEK with carbon fiber filler. Thesematerials are dissimilar with respect to their morphological structureand their processing temperatures. Other pairs of morphologicallydissimilar materials could also be utilized with similar advantages asprovided by these materials. The amorphous material, polycarbonate, andthe crystalline material, PEEK, form a thermophysical bond when theamorphous material comes in contact with the crystalline material inmolten state. It is believed that the bond is formed by the virtue ofthe increase in surface energy of polymer glass at the interface.Therefore, when the hot amorphous melt comes in contact with the polymerglass, the polycarbonate, it elevates the surface energy of the polymerglass and as the hot melt is cooling down, it crystallizes at theinterface. It is theorized that the crystallization process attributesto the bond of the two materials. The heat dissipates into the polymerglass at a very slow rate because of its low specific heat and thus thehot melt of PEEK cools at a lower rate increasing the crystallinity atthe interface. When this process is carried out in an injection mold,the product formed will have higher crystallinity level at the interfaceof the polymer glass and crystal than at the interface of the polymercrystal and the mold steel because of the difference in specific heat ofsteel and polymer glass.

[0049] In a preferred embodiment, the polycarbonate, that is the polymerglass, the support portion, would be molded first and then placed backinto an injection mold to mold the operative portion of PEEK over it. Inthis process the mold temperature is ideally kept below the glasstransition temperature of polycarbonate which is approximately 149° C.to prevent distortion of the polycarbonate base portion. The wafercontact portion 50 is strategically positioned and configured such thatthe wafer shall never come into contact with the polycarbonate.

[0050] An alternative amorphous material in which a favorable bond hasbeen observed is polyetherimide (PEI). This bond may have a chemicalbonding component.

[0051] Various types of bonding components may be involved in thebonding of the overmolded portion to the base portion. It is believedthat a thermophysical bond occurs when the molten overmolded materialcomes into contact with the non-molten base portion. Thermophysicalbonding occurs when the molecules of the two portions come within threemolecular radii.

[0052] Referring to FIGS. 3, 4, and 5, a work-in-process box isdisclosed and is generally indicated with the numeral 60. Such a boxwill typically hold an H-bar wafer carrier 62 and has principalcomponents of a top cover 64, a base portion 66, and an H-bar wafercarrier 62 engaged in and seated on the base portion 66. In this case,“carrier” references either the enclosure box or the enclosure box withthe H-bar carrier. Several components may be formed in the overmoldprocess to take advantage of the inherent features and advantages of theprocess and the invention. For example, in FIG. 5 the top section may bemolded of polycarbonate with the hinge 68 overmolded with PEEK to adhereto the top cover section 64. Moreover, referring to FIG. 4 apolycarbonate window 70, an operative portion, may first be molded of adesired configuration and size and inserted into the mold for the coverportion 64, the support portion, with the balance of the cover portionovermolded to the polycarbonate window. The overmolding allows andprovides a juncture of high integrity without the use of adhesives ormechanical fasteners.

[0053] Referring to FIGS. 6 and 7, a magnetic disk shipper carrier istypically comprised of a base portion 76, a top cover 78, and portion 79may be advantageously formed according to the invention by first moldingthe support portion 82 of the base portion 76 and then injection moldingthe disk engaging portions 84. Again the support portion 82 may beformed of polycarbonate or similar material and the disk contactingportions may be formed of PEEK or similar material.

[0054] Referring to FIGS. 8 and 9, a transport module, which is intendedfor use with large semiconductor wafers, for example 300 mm, is shown.In this particular configuration the wafer support portion 90 iscomprised of a base 91 with a machine interface portion 92, uprightcolumns 94 with wafer support shelves 96, and a top portion 98. Thewafer engaging shelves may have an overmolded portion 99, an operativeportion, which is the portion that contacts wafers contained by thetransport module. The machine interface also may utilized an overmoldedportion where it contacts equipment.

[0055] Referring to FIG. 12, an alternate embodiment of a wafer carrierconfigured as a process enhancement carrier is shown and is generallyindicated with the numeral 110. Such process enhancement carrier hasbase support portions 112 and 114 as well as arms 116 extendingtherebetween. Each of the arms has a plurality of teeth 118 which defineslots 120 for holding wafers during processing steps. In this particularembodiment the exterior portion of the arms 116 and the teeth may heovermolded to a basic base framework 122 to provide the advantages ofthe invention.

[0056] Referring to FIGS. 10 and 11, a composite wafer carrier made ofassembled components 122 is disclosed. Components comprise sidewallportions 124 as well as a carrier framework 126. The side wall inserts124 fit within and engage the framework 126 to form a secure andassembled wafer carrier. Additionally, a robot flange or machineinterface 132 may be provided on the rear end 134 of the carrier. Inthis case each of the sidewall portions may have overmoldedwafer-engaging portions 139 in order to minimize particle generation bythe scrapping of the wafers. The overmolding can be under tighterdimensional control than the base portion to provide low tolerancepositioning of the wafers.

[0057] Referring to FIG. 14, a composite wafer carrier according to anembodiment of the present invention is shown. The carrier 200 is aFOUP-type carrier having a front opening door 202. The door is providedwith a transparent window 204, thereby permitting inspection of thewafers contained within the container 200. The presence of the window204 allows the use of conductive plastics for the remainder of the doorstructure. Conventional conductive plastics known to those of skill inthe art are not transparent. A plurality of gradations 206 may beprovided to the window 204 for ease of quantifying the number of wafersin a given container 200. It should be appreciated that the windowlocation and size may be varied without departing from the spirit orscope of the present invention.

[0058] Referring to FIG. 15, an assembly view of a door latchingmechanism is shown according to an embodiment of the present invention.U.S. Pat. No. 5,915, 562, to Nyseth et al., discloses door lathingmechanisms in greater detail, and is hereby incorporated by reference.The door latch mechanism 208 of door 202 includes a bearing protrusion210. The bearing protrusion is provided to the door 202 as part of anovermolding process, as described herein. The composite door allows foran abrasion resistant material, such as peek, to be used for the bearingpost 210, while still using polycarbonate or conductive plastics for theremainder of the door 202.

[0059] Referring to FIG. 16, a cover for a wafer enclosure is shown. Thecover or door 300 comprises a body 302, door latch assemblies 304disposed within the door 302 and latch assembly covers 306 for enclosingthe latch assemblies 304 within the door 302. Each latch assemblycomprises a latch actuator 308 disposed on a bearing post 210 (shown inFIG. 15), latch members 310 operably joined to the latch actuator 308and a resilient latch assist device 312 also operatively joined to thelatch actuator 308. The latch actuator 308 comprises a cammed wheel 314and a key slot 316 disposed within the cammed wheel 314. The key slot316 is configured to receive an actuator key, which is used by anoperator or automated machinery to selectively latch or unlatch thecover 300.

[0060] Referring to FIG. 13 a schematic view illustrating a methodologyfor accomplishing the invention is shown. First a mold is provided formaking a base or support portion, which can be a carrier framework orother carrier portion such as a sidewall base portion 130 as isillustrated. The base portion is molded and is then put into anadditional mold or alternately the same mold with a mold insert removed.Then the mold is closed and additional overmolding material such as PEEKis injected into the mold cavity, which corresponds to the specificoperative portions, which are being overmolded. Then the completedportion which comprises the support portion and the overmolded operativeportion is removed. If such a base portion is a component part then thecomponent part is assembled into a carrier 136. It should be recognizedthat the support portion may be overmolded on the operative portion.

[0061] In particular applications it may be suitable to have the firstinjection molded portion, the base portion to be relatively smallervolumetrically than the second, overmolded portion. In otherapplications a first material may be deposited at critical positions ina mold, for example the wafer contact areas, the material is allowed tosolidify, and a second support portion is overmolded onto the firstmaterial without changing molds.

[0062] In other particular applications, the second material does nothave to be allowed to solidify; the two materials may join while bothare molten. This co-injection molding may not offer the precision inlocating the interface between the first portion and the second portion;it does, however, eliminate the need for the extra mold and the steps ofallowing the first portion to solidify, removing the portion from themold, and placement of the first portion in a second mold.

[0063] The present invention may be embodied in other specific formswithout departing from the spirit of essential attributes thereof, andit is therefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive, reference being made tothe appended claims rather than to the foregoing description to indicatethe scope of the invention.

What is claimed is:
 1. A process for manufacturing a wafer carriercomprising the steps of: injection molding a transparent window portionof a first plastic material in a first mold; placing the moldedtransparent window portion in a second mold; and overmolding a waferenclosure portion to the transparent window portion using a secondplastic material in the second mold, wherein the wafer enclosure portiondefines an enclosure for enclosing a plurality of wafers, wherein thesecond plastic material is different from the first plastic material,and wherein the second plastic material bonds with the first plasticmaterial without mechanical fasteners between the wafer enclosureportion and the transparent window portion.
 2. A composite wafer carriercomprising: An enclosure portion formed of a first thermoplasticmaterial and a second plastic material, the wafer carrier enclosing aplurality of slots for holding wafers in an axially aligned arrangement,the enclosure portion including a transparent window formed of the firstthermoplastic material thermophysically bonded within a support portionformed of the second thermoplastic material for allowing the wafers tobe viewed through the window, and wherein the window portion is securedin the enclosure portion without separate mechanical fasteners.
 3. Thewafer carrier of claim 2, wherein the window comprises a plurality ofgradations provided thereto for indicating a relative number of waferscontained within the wafer carrier.
 4. The wafer carrier of claim 2,wherein the second thermoplastic material is an electrically conductiveplastic.
 5. A composite wafer carrier having a plurality of slots forholding wafers in an axially aligned configuration, the wafer carriercomprising: a container portion comprised primarily of plastic andhaving an opening on one end; a door configured to latch onto andsealingly close the opening, the door comprised of a latch portionhaving an operative portion and a support portion, the operative portionformed of a first thermoplastic material, the support portion formed ofa second thermoplastic material, the operative portion and the supportportion having a thermophysical bond therebetween formed fromovermolding one of said support portions and operative portion on theother of said support portion and operative portion, whereby saidportions are bonded together without separate mechanical fasteners. 6.The wafer carrier of claim 5, wherein the second thermoplastic materialcomprises polycarbonate and the first thermoplastic material comprisespolyetheretherketone.
 7. The wafer carrier of claim 5, wherein theoperative portion is configured as a bearing post.
 8. The wafer carrierof claim 5, wherein the latching mechanism comprises a cammed wheel witha key slot therein and the operative portion includes the key slot.
 9. Amethod for forming a composite wafer carrier, the method comprising thesteps of: forming a transparent window portion in a first mold, thewindow comprised of a first material; placing the transparent window ina second mold; injecting a second material into the second mold to forma wafer carrier.
 10. The method of claim 9, whereby the window islocated within the wafer carrier in a position for allowing a pluralityof wafers contained within the wafer carrier to be viewed through thewindow in a direction generally transversely to an axial alignment ofthe plurality of wafers.
 11. The method of claim 9, wherein the windowis bonded to the wafer carrier without mechanical fasteners.
 12. Themethod of claim 9, wherein the step of injecting a second materialcomprises melting an electrically conductive plastic.
 13. A process formanufacturing an integral composite wafer carrier component, the processcomprising the steps of: injecting a first thermoplastic material into amold to form an operative portion; and injecting a second thermoplasticmaterial of a different composition than the first contacting theoperative portion while the second material is molten to form a supportportion, thereby forming a gapless hermetic interface between theoperative portion and the support portion securing said portionstogether.
 14. The method of claim 13, further comprising the step ofselecting a transparent polycarbonate as the first thermoplasticmaterial.
 15. The method of claim 13, further comprising the step ofselecting a first thermoplastic that has one of the followingcharacteristics: abrasion resistance and static dissipative.
 16. Themethod of claim 15, further comprising the step of forming a cammedwheel from the operative portion and support portion.
 17. The method ofclaim 15, further comprising the step of configuring the operativeportion as a bearing post for a latching mechanism.
 18. A process formanufacturing an integral composite wafer carrier portion comprising:injecting a first thermoplastic material into a mold cavity at apredetermined location to form a window portion, wherein the firstthermoplastic has the characteristic of transparency; injecting a secondthermoplastic material contacting the first material while the secondmaterial is molten to form a wafer carrier portion with an interfacetherebetween; and allowing the second portion to cool therebysolidifying the second thermoplastic material and thereby forming agapless hermetic interface between the window portion and the wafercarrier base portion, wherein the window portion allows a user to view aplurality of wafers contained within the wafer carrier portion.
 19. Awafer carrier comprising: an enclosure enclosing a plurality of slotsfor holding a plurality of wafers, the enclosure comprising atransparent window with a peripheral edge thermophysically bonded withinthe enclosure to the enclosure to a window support portion, thethermophysical bond formed by overmolding.
 20. The wafer carrierapparatus of claim 19, wherein the wafer carrier comprises an H-barwafer carrier and the plurality of slots are defined by said H-barcarrier.
 21. The wafer carrier of claim 19, wherein the enclosurecomprises a base portion and a cover.
 22. The wafer carrier of claim 21,wherein the cover includes a latching mechanism therein for releasablysecuring the cover to the base portion, the latching mechanism includinga bearing post overmolded with the cover.
 23. The wafer carrier of claim19, wherein the window comprises a plurality of gradations providedthereto for indicating a relative number of wafers contained within thewafer carrier.
 24. A process for manufacturing a wafer carrier componentcomprising the steps of: injection molding a transparent window portionof a first plastic material in a first mold; placing the moldedtransparent window portion in a second mold; and overmolding a waferenclosure portion to the transparent window portion using a secondplastic material in the second mold, wherein the wafer enclosure portiondefines an enclosure for enclosing a plurality of wafers, wherein thesecond plastic material is different from the first plastic material,and wherein the transparent window portion is secured within the waferenclosure portion without mechanical fasteners between the waferenclosure and the transparent window portion.
 25. The process formanufacturing a wafer carrier of claim 24, further comprising the stepof selecting the first plastic and the second plastic such that when thesecond plastic is overmolded to the first plastic a gapless hermeticinterface is formed.